Method for enhancing the growth of plants



Patented Dec. 27, 1927.

V UNITED STATES.

CHARLES F. ECKAR'I, O1 OAKLAND, CALIFORNIA.

METHOD FOBENHANGING THE GROWTH OF PLANTS.

No Drawing.

The invention relates to a method of enhancing the growth and increasing the yield of certain plants, especially perennials like asparagus which sprout from parent stock 5 at seasonal intervals, the method involving a special mulching operation to effect the exclusion of rainfal from the plant beds and facilitate the slow evaporation of moisture contained in said beds prior to and during the period of initial underground growth of the plants and at the same time to increase thetemperature of the soil constituting the plant beds or planted areas by the absorption or dissemination of solar heat, the

method comprising covering the planted areas prior to and during the period of initial underground growth of the-plants with a material substantially impervious to rainwater and pervious to slowl evaporated moisture. from the soil, where y ideal conditions of heat and moisture aremaintained to cause earlier sprouting and to effect an optimum growth and development of the plants; the covering material also being of a character to absorb solar heat and transmit the same to the subjacent soil, so that, when the plants have obtained their initial underground development and begun to sprout, and the coverings are removed, the stimulation given the mother root system and the underground buds or other sprouting elements, prior to the removal of the cove'rin material, will insure the continued hastene sprouting and enhanced development of the crop, comprisin the plants, for a considerable period, an a relatively large increase in the yield of early harvest will be derived therefrom, together with a substantial ain in the amount of the total crop produced As exemplifying the eflicacy of the present method, the application of the same to the cultivation of asparagus and the resultant marked increase in the yield as a consequence thereof, will be described. It is well known ill at that the best asparagus producing areas involve relatively light'soils that are highly pervious to and retentive of moisture. It is also well known that marketable asparagus shoots spring seasonally from root stock W usually established in rows that are billed up or laid out in ridges. As the more productive asparagus growing sections are usually in the belts of copious rainfalls in the pe riod immediately rior to and during the initial undergroun growth of the plant, it

has been found that the, absorption ofexces- .a u auoa flied may 19, 1927. Serial m.-192,790.

sive moisture by the soil of the asparagus beds retards the sprouting of the early shoots and decreases the yield of product at a time when the condition of the market is most favorable, the retardation of the shoots being due chiefly to the lowering of the temperawhich is known to be the largest asparagus growing section in the world. In this loca-' tion, as aragus is grown in ridges or continuous ills in soil which for the most part is fairly; high'in organic matter and some:

.what peaty in character. Under normal conditions, the first shoots of the asparagus usually appear about themiddle of February, but not inanyquantit About the first of March, the supply 0 shoots is increased and from the middle of March onward or until June, the supply is plentiful. The harvesting season ordinarily ends about the first of June, and such shoots as come up subsequently are allowed to go to tops and ferns, which means that the young shoots instead of being harvested are permitted to grow into mature-plants, so that the root stock in the soil may expand and develop into vigorous condition for sprouting a good crop of fresh young shoots the following season. The first frosts in the-latefall or early winter kill the mature asparagus plants, which are then out down and removed or burned and the field put in shape for the sprouting of the next cro of young tendershoots in the succeeding llite winter or early spring.

I have discovered a method whereby the soil may be kept) drier and warmer during the period of greatest rainfall in the winter time, and a special stimulus thereby be iven the crowns or bud-bearing parts 0 the asparagus roots to cause t em to sprout earlier on an average than they would, so that not only an earlier but also a more abundant harvest will result. In accordance with my method, I apply to the ground, as hereinafter setforth in detail, a covering of such a nature as to substantially exclude moisture externally applied,'as by natural rainfall, and yet allow a slow evaporation of the moisture from the soil, while at the same time delivering to the soil as otherwise much solar heat as possible to maintain the temperature of the soil most favorable to the early developmentand enhancement of the plant owth. To this end, I use preferably a special form of strip mulch, which is practically impervious to and, therefore, capable of shedding water externally applied, as by natural rainfall thereby preventing the direct entrance of such water into the subjacent soil, but which permits absorption and slow evaporation of a portion of the moisture from the soil through the body of the mulch and which mulch also has inherent heat absorbin qualities, which permit it to take up the so ar heat and transfer the same to the subjacent soil containing the plant stock; whereby optimum conditions of temperature and moisture in the soil for enancing the growth and development of the plants are ap roximated. It is necessary to rovide for t is slow evaporation of water mm the soil below to take place in order to offset the amount of water gainin entrance laterally under the edges of the mulch, because of the capillary and absorptivecharacteristics of the soil.

I have found that continuous strips of specially constructed paper comprising a mid- 1 dle layer of asphalt impregnated fibers with w upper and lower layers of unimpregnated fibers, the upper surface of this composite paper prefera ly being black or dark in color to render the same heat absorbing, produce the desired results. This particular type of paper was found to be substantially waterproof or impervious to rain-,'

, fall, but quite pervious to slow evaporation of moisture from the soil, this moisture condensing on the under side of the paper and 40 beinggradually absorbed into the more or less porous fabric thereof, and being gradu ally dissipated by evaporation. Strips of this paper of suitable width are laid upon and along the rounded tops of the ridges of the aspara s producing area, the edges, of the strips eing held down by any suitable means, as for example, by earth thrown on the edges -y means of disk plows or hoes, the mulching strips being thus held firmly in position overlying the surface of the soilcontaining the roots and covering practicallythe entire plant producing area. These mulching strips are preferably laid in position prior to the initiation of the underground growth of the plants and are maintained in position until the early underground bu s are close to their sprouting time or have sprouted and the resulting. shoots have begun to emerge through the soil, after which the mulching stri s are re-' moved and'the development of t e plants is permitted to continue under normal naturaliconditions.

, Several large size experiments with this particular type of mulch, of different widths and laid at different times, were carried out in the California section hereinbefore referred to, where the aspara us fields were laid off in rows or ridges thirteen hundred and fifty feet in length and, as the results of all of the tests were consistent with respect to the marked effect of the paper, the application and result of one of the tests will be detailed.

On January 30th, there was laid a number of long strips (in this particular instance forty-eight inches wide) of this special type of mulching paper on a number of rows or ridges of asparagus beds. Each of these rows was approximately one-quarter mile long. At this time, of course, the rows were bare a i 1 l the strips of paper were superimposed on the ridges in surface contact with the soil, the edges of the paper being held down by means hereinbefore referiaad to; These mulches were permitted to lie undisturbed until February 26th, when they were removed from the field. It was found that the soil of all the ridges, which had been protected by the mulches between January 30th and February 26th was soft, dry and friable as compared with the soilin the adjacent ridges which had not been so protected, and it was also found that the soil of the underlying asparagus beds was maintained at a hi her temperature, as evidenced by repeate observations, than that ofthe adjacent untreated beds, the reasons for these conditions apparently being as follows 1. They contained less moisture;

'2. They were protected from the wind and, therefore, from the cooling effect roduced by hastened evaporation induce by wind; and i 3. The color of the u er surface of the mulching paper being qu lack, considerable solar heat was absorbed by the strips and distributed to the soil. This higher soil temperature prevailed during the time the beds were covered with the mulching slri )S, and also to a less degree for a considera le period after the aper was removed.

The stimulation given the underground crowns or 'buds by this method was most striking and pronounced. Fifteen cuttings (harvestings) of green as aragus shoots were made and the effect 0 the mulching operation" on the sprouting of the buds persisted after the aper had been removed from the field. p to and including a cutting made on the 27th of March, the total gain in wei ht of the crop taken from the mulchedbeds over those to which no paper had been applied was 149%. Furthermore,

the average shoot from the ridges which had been mulched was 21% larger than the average shoot from the ridges not so protected. This large gain in the weight of crop taken off during the first stages of the ill harvest in March was due mainly to the fact that the crop was advanced, so that the shoots which would not have come up until April were induced to sprout in March and, lilrewise, the shoots which "would have come up after the middle of March were forced to sprout during the first half of the month and so on. It will be seen, therefore, that the method not only involves the production of earlier crops, but of larger andfar more valuable crops, both as to the extent and quality of the yield.

While the invention has been particularly described with reference to enhancing the growth of asparagus, it will be apparent that it is not limited to this particular application, but may be used with favorable results with other crops where similar conditions prevail.

What l claim is:

l. The method of enhancing the growth of plants which comprises covering the planted or hearing areas, during a period prior to the emergence of the plants above the ground, with a material in surface contact therewith capable of shedding rainfall and of reducing the amount of moisture beneath the same by absorption and evaporation.

The method of enhancing the growth of plants which comprises covering the planted or hearing areas, during a period prior to the emergence of the plants above the ground, with a heat-absorbing material in surface contact therewith capable of shedding rainfall and of reducing the amount of moisture beneath the same by absorption and evaporation.

3. The method of enhancing the growth of plants which comprises covering the planted or bearing areas, during a period prior to the emergence of the plants above the ground, with a material in surface contact therewith capable of shedding rainfall and of reducing the amount of moisture beneath the same by absorption and evaporation and removing said covering before the emergence of the plants from the ground.

a. The method of enhancing the growth of plants which comprises covering the planted or bearing areas, during a period prior to the emergence of the plants above the ground, with a heat absorbing material in surface contact therewith capable of shedding rainfall and of reducing theamount of moisture beneath the same by absorption and evaporation and removing said covering before the emergence of the plants from the ground.

5. The method of conditioning soil as to temperature and to moisture content for enhancing the growth of plants which consists in placing in surface contact with the soil a material capable of shedding rainfall, and of reducing the amount of moisture beneath the same by absorption and evaporation.

In testimony whereof I affix my signature.

CHARLES F. ECKART'. 

